How many atoms are in the average cubic square of interstellar space?

1 Answer
Waleed A.
Nov 19, 2015

1/4 or 0.25 atoms/ #m^3#

Explanation:

It has been calculated that there are roughly 0.25 atoms per cubic meter of interstellar space.

No. of atoms / cubic meter = Density of the Universe/ Mass of an atom

Density of the Universe = 5 x #10^-28# kg/ #m^3#
Mass of an atom = 2 x #10^-27# kg

No. of atoms/ cubic meter = 5 x #10^-28#/ 2 x #10^-27#

No. of atoms/ cubic meter = 1/4 or 0.25 atoms/ #m^3#

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